Ape Genius

(This program is no longer available for online streaming.) At a research site in Fongoli, Senegal, a female chimpanzee breaks off a branch, chews the end to make it sharp, and then uses this rudimentary spear to skewer a tasty bush baby hiding inside a hollow tree. It's an astonishing breakthrough for primate researchers—the first time anyone has documented a chimpanzee wielding a carefully prepared, preplanned weapon. But it's only the latest in a slew of extraordinary new findings about ape behavior.

The more researchers learn about the great apes—chimpanzees, bonobos, gorillas, and orangutans—the more evidence they find of creative intelligence. What, then, is the essential difference between them and us? "Ape Genius," a NOVA-National Geographic special, explores that provocative question and examines research that is illuminating the ape mind. Bit by bit, investigators are finding an explanation for why the non-human great apes never made the breakthrough into a human-style culture that builds on the achievements of previous generations.

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Ape Genius

PBS Airdate: February 19, 2008

NARRATOR:
Something strange is happening in the forests of
Africa. Chimpanzees are doing things no one has seen them do before: they are
having pool parties. But that's not all. At a site called Fongoli, in
Senegal, they have also invented a remarkable way to catch a meal. They are
making spears and hunting, just like our ancestors.

Fresh
steaks and a swimming pool? How long until they fire up the barbecue? After
all, the great apes—chimpanzees, orangutans, gorillas, and bonobos—seem
so much like us, it's hard not to feel a deep connection.

MICHAEL
TOMASELLO
(Max Planck Institute for
Evolutionary Anthropology)
:
We
have come to see that we're much more similar to them than we ever
imagined.

NARRATOR:
But for every revelation about the power of their
minds, another shows up a stunning difference.

REBECCA
SAXE
(Massachusetts Institute of Technology)
:
If you think that human genetics and ape genetics
are 99 percent the same, what we've managed to achieve in our current
position on Earth is so strikingly different from that of apes.

BRIAN
HARE
(Duke University)
:
We're trying to figure out, "What is it
that makes us human? What's the little difference that makes the big
difference?"

NARRATOR:
How big is the gap between them and us?
What's holding them back? Inside ape minds, right now on this
NOVA/National Geographic special.

Major funding for NOVA is provided by David H.
Koch. And...

Discover new knowledge: HHMI.

And by the Corporation for Public Broadcasting, and
by contributions to your PBS station from viewers like you. Thank you.

NARRATOR:
In a remote part of Africa, there's
something new under the sun. Our closest living relatives are getting bold.
Chimps are supposed to be afraid of water, but this young male is climbing down
for a dip. He keeps a hand on a natural safety line as he overcomes his fear.
Has a boy or girl ever had more fun in a swimming hole? Wild chimps have never
before been seen playing like this.

ANDREW
WHITEN
(University of St. Andrews)
:
The personality of a chimpanzee is extremely
excitable. I've hardly ever seen a facial expression like that. I mean,
that was extreme excitement to the stage of kind of losing control.

JILL
PRUETZ
(Iowa State University)
:
It's not merely just to cool off. The
juveniles have fun. I mean, they play in the water. They play a lot in the
water.

NARRATOR:
This is only one of a rush of discoveries that is
painting a surprising new portrait of ape minds. They are more like us than
most researchers ever imagined.

One
by one, the skills and emotions we once thought were uniquely human are being
found in apes. Still, certain specific mental gaps—the little differences
that make the big difference—will ultimately explain why we study them
and not the other way around.

While
the swimming hole is revealing chimps' emotions in the field, a new
laboratory study is showing off their amazing rational powers.

At
the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany,
psychologist Josep Call places a peanut in a clear tube.

How
can the chimpanzee get the snack? She has never seen this puzzle before.

JOSEP
CALL
(Max Planck Institute for
Evolutionary Anthropology)
:
For
10 minutes, there is no solution in sight. And all of a sudden, boom, they
solve it. They have to understand that they can use the water as a tool. This
is interesting, because the water itself, it doesn't have any shape.

NARRATOR:
Using water as a tool seems like something we
would do—on a good day.

Another
tool is being put to remarkable use by wild chimps in their quest for a meal.
Back in Senegal, Jill Pruetz has been keeping a close eye on chimps'
eating habits. Throughout Africa, chimps eat almost anything, and they have a
particular taste for meat. Here, their favorite prey is the bush baby, a small
nocturnal primate.

But
these chimps aren't catching bush babies barehanded. Pruetz has seen
chimps making spears and using them to hunt.

Andrew
Whiten hopes to join the ranks of the few who have witnessed this extraordinary
behavior.

Pruetz
has just collected a spear jammed in the top of a dead tree.

JILL
PRUETZ:
So I'd say, I guess, this one is longer than
average.

ANDREW
WHITEN:
Yeah, this is a big, long and
fairly stout one.

JILL
PRUETZ:
Yeah, yeah.

ANDREW
WHITEN:
But the length of it's
interesting, because that's a big hole. And this thing's pretty
well judged to more or less reach to the end of it in a firm way.

JILL
PRUETZ:
It's pretty precise.

NARRATOR:
To make a spear, a chimp starts by breaking off a
branch, then sharpening the tip, all in the quest to catch a bush baby in its
daytime sleeping hollow.

JILL
PRUETZ:
So the next step would be that the chimp would
approach the cavity and sometimes look in, take the tool, jab forcefully into
the cavity, multiple times.

NARRATOR:
It may not be ice-pick-sharp, but when driven by
an arm up to five times as strong as a human's, it's a potentially
lethal weapon.

JILL
PRUETZ:
They always either sniff it or lick it when they
withdraw the tool. What they may do is actually break open the entire cavity
and, if they're lucky, find a bush baby inside.

NARRATOR:
Break, strip, sharpen, stab: these chimps take a
series of distinct steps in a carefully premeditated hunt.

For
Andrew Whiten, this discovery may offer a window on our own past.

ANDREW
WHITEN:
Hunting's fascinating to us
humans, particularly if we're interested in the evolutionary story of how
we got here. Our ancestor, five or six million years ago was somewhat like a
chimpanzee, we know that. Then, later in the evolutionary story, we became big-game
hunters, using a lot of weaponry, butchery tools. And we're bringing down
large prey. So how did an animal like a puny ape reach that stage?

NARRATOR:
Pruetz and Whiten are closing in on the answers.
Most of the 20 spear hunts Pruetz has observed have taken place during the
rainy season. Over time she has seen every stage of the kill.

A
chimp is inspecting a hollow, looking for a bush baby. She breaks off a branch
and makes a spear.

JILL
PRUETZ:
The first time I saw a chimp make a tool, I think I
said something like, "Where is she going, and what is she going to do
with that tool?"

NARRATOR:
She nibbles the tip to sharpen it. Then, with the
aid of her foot, she aims the point into a hollow.

Pruetz
has made a landmark discovery. Never before has any non-human species been
known to routinely make and use deadly weapons.

So
what does spear-hunting reveal about how chimpanzees think? Pruetz and her team
have seen about half the chimps here brandishing weapons, which means spear
hunting has spread through much of the group. That seems natural to us. But
generating ideas and sharing technologies? That's one scientific
definition of culture.

For
Whiten, culture includes the human arts from opera to Oprah, but it also covers
the rudimentary traditions of ape societies.

ANDREW
WHITEN:
If you know enough about the
behavior of an individual, you actually know where they come from. So if you
know someone who wears a tartan kilt, and to play the bagpipes, if they enjoy
porridge for breakfast, they probably, you can tell, come from Scotland. So if
you know that a chimpanzee is one of several in its group that enjoy coming and
dunking themselves in a pond, like this, and also that they sharpen sticks and
actually use those as primitive kinds of weapons then, "Aha! That
chimpanzee comes from Fongoli."

NARRATOR:
Whiten is trying to discover what kind of mind can
lead an ape to culture.

ANDREW
WHITEN:
Young watch their parents,
sometimes very intently. And over the following months and years, they acquire
that behavior. So you have to be able to copy.

NARRATOR:
When apes live alongside people, they sometimes copy
our behaviors naturally, without any training. Copying someone else's
successful actions beats reinventing them from scratch, but it's a lot
harder than it looks.

When
these bonobos in the Congo started imitating each other, it seemed like play.
But they were actually relying on a sophisticated skill-set for copying.

REBECCA
SAXE:
You see some
other animal doing something that you want to do. And being able to figure out,
just by watching how they're doing that, so you can do it yourself, is
actually an incredibly complicated skill, with lots of steps to it.

You
have to know what it is about what they're doing that leads to some goal
that animal has. You have to be able to know enough about that goal to
recognize that you share that goal. You have to know, "How is it
physically working?" You have to know enough about your body and other
bodies to be able to line them up.

NARRATOR:
To prove that one ape can copy another, a student
of Andrew Whiten's devised an experiment. At the Keeling Center of the
University of Texas, Antoine Spiteri has built a kind of slot machine for apes.
He loads it with a grape.

To
get the fruit, a chimp must first turn a disk to allow the grape to drop
through a hole. Next, a chimp has to move a handle that opens a door to release
the fruit pay-out.

Spiteri
now trains a chimp named Judy how to work the device. On her own, she'd
never figure it out, but thanks to a sweet liquid reward, she learns the
sequence of two steps: rotate, then push. Ka-ching!

Next,
Judy's group mates enter the corral. Spiteri wants to know if, just by
watching, the chimps in the peanut gallery will learn the technique. Can these
apes ape to win this food-finding game? One chimp seems to think she's
got it and shoves Judy aside.

A
minute ago, Judy was the only one with the knowledge. Now another has it, and,
quickly, the trick spreads throughout the group.

But
for Spiteri, the most important question remains. Have the kibitzers next door
also learned the solution? They have no social ties to the original group. In
fact, they are hostile to them. Would they set that aside to keep with the
Joneses next door?

In
no time flat, they're working the slot machine like old pros. Rotate.
Then push the handle. Call it the Texas two-step.

Learning
by imitation is an essential skill for culture. And culture, along with the
complex thoughts and emotions behind it, were long believed to be uniquely
human.

MICHAEL
TOMASELLO:
The history of Western thought
has always been premised on the idea that there are beasts and there are humans;
and humans are touched by the spark of God, and beasts are just beasts.

NARRATOR:
Something of a revolution came in 1960, when a
young researcher, with support from the National Geographic Society, set up
camp in Tanzania. Jane Goodall observed that chimps' emotions seemed much
like ours, especially the tenacious bond between mother and baby.

At
a site called Bossou, in Western Africa, Japanese researchers recorded the
story of an ill two-year-old chimp. Her mother touches her forehead as if to
check for fever. As the baby's strength ebbs her mother remains devoted.

TETSURO
MATSUZAWA
(Kyoto University)
:
When I see the scene of the mother looking at the
baby, I really recognize the emotional life of chimpanzees are so similar to
us.

NARRATOR:
For weeks after the baby's death, her
mother carries the body. Is the mother grieving? Defiant? Can an ape be in
denial? It's impossible to say exactly what the mother is thinking, but
hard to dismiss her feelings.

Putting
ape emotions on the map was only one of Goodall's accomplishments. She
also found powerful evidence of their intelligence. Goodall was the first to
report chimps making and using tools—in this case to "fish"
for termites.

TETSURO
MATSUZAWA:
When she found termite-fishing,
people were so surprised, and thought we should change the definition of humans,
or we should include chimpanzee as humans.

NARRATOR:
What Goodall couldn't have known was that
at a place called Goualougo, other chimps had an even more sophisticated way to
catch termites. First they use a big stick like a shovel to open the ground,
then they switch to a slender probe to pull up the insects.

Perhaps
Goodall's most astonishing discovery was that chimps are hunters. She
watched a troop catching colobus monkeys by hand.

Although
no one has established that they actually coordinate their efforts, the chimps
seem to be cooperating. And cooperation is, after all, one of the key drivers
of human culture. Could apes rev up their culture by working together? Imagine
a group of chimps, armed and dangerous, hunting as a band.

So
why isn't Earth Planet of the Apes?

Do
apes even have the capacity to cooperate? A series of new studies reveals the
rudiments of teamwork in the great apes. But they still come up short.

In
an experiment at the Great Ape Research Institute in Japan, a chimp knows that
food is hidden under a stone. Then researchers swap in a heavier stone. If two
chimps each know about the food, can they work together?

In
repeated trials, no pair of chimps ever communicated to synchronize their
pulling. Swap in a person—researcher Satoshi Hirata—and chimps
still don't collaborate, at first. But, eventually, they figured out the
sweet rewards of cooperation. Ultimately, the chimps learned to ask for a
helping hand.

A
needy chimp may recruit help from a person, but will it ever offer assistance?

MICHAEL
TOMASELLO:
One of the most surprising
findings of all of my years of studying apes has been that they will actually
help humans. If you're reaching for an out-of-reach object, if they
understand what your goal is, then they will help you.

NARRATOR:
Of course if you've dropped your banana,
forget it, you won't get it back.

Chimps
can understand what someone else wants. And one study shows that they can even
interpret another's actions as good or bad.

In
Leipzig, Germany, a chimpanzee is about to receive a tray of monkey chow. At
the same time he's given a rope under the platform he can pull anytime to
collapse the platform and end the experiment. Another chimp now enters the
cage. This chimp is free to pull a second rope on top of the tray. The first
chimp is ticked off. He pulls the hidden rope, and the game's over.

Was
he just generally outraged? Or was he taking specific revenge on the thief? To
find out, the researcher now moves the food. Once again the first chimp has
lost his food to the second. All that's changed is who's
responsible.

In
trials where the researcher moves the chow, the first chimp is much less likely
to crash the platform. That would punish an innocent chimp who had no intent to
do him wrong.

JOSEP
CALL:
They can gauge who is responsible for something that
has been done. Humans make a big distinction on...intentions are very important
for humans. For instance, take the case...in our judicial system, manslaughter
and murder; the difference between those two is simply the intent.

NARRATOR:
So chimps have a sense of justice, and they can
cooperate with people. Can they collaborate spontaneously with each other?

Researchers,
also from the Max Planck Institute, placed fruit on a board just out of a
chimpanzee's reach. The chimps are behind bars, both to keep them from
the food, and because they can be impulsive, strong and dangerous.

When
a solo chimp can reach both ends of a rope, it hauls them in and gets all the
food. But on some trials the ends are too far apart. If the chimp pulls just
one end, the rope unthreads.

The
chimp has another option. He can unlock a door to bring in a helper who's
been watching. The two chimps now work together.

But
a series of trials shows that this teamwork doesn't come easily. The
helper must be a friend, and the food divided into separate dishes.

Can
a more loving ape cooperate better? At Lola Ya Bonobo Sanctuary in the Congo,
victims of the pet trade are raised by human mothers. When these bonobos grow
up, they will spend their days outdoors, becoming savvy about life in the
forest. Bonobos are the most social of the great apes. And in their groups, all
friends are "friends with benefits," a simple way to diffuse
tension.

Calmer
than chimps, how do bonobos do on the cooperation test? Brian Hare places food
in a central shared well.

BRIAN
HARE:
All the food is in the same dish, so it's very
easy for one individual to bump the other individual out of the way and steal
it all.

NARRATOR:
It takes the bonobos a while to get on task. But
soon they get the hang of it.

BRIAN
& ESTHER :
Yay, bonobos! Yay!

NARRATOR:
With their more congenial temperaments, bonobos
are more cooperative than chimps are. In fact, bonobos may take cooperation
even further.

When
a young male died at Lola Ya Bonobo, workers were trying to remove his body.

BRIAN
HARE:
The staff decided to use sticks and try to move the
bonobo towards a door. They mounted an incredible defense of this body that
surprised everybody and was extremely moving. That's a fascinating
reaction on the part of the bonobos. They were not related to that individual,
and yet, they took extreme risks to protect his body.

NARRATOR:
As they fend off the humans, it seems as if
they're cooperating. But what does it take to work together? Are they
comparing the number of staff to their own troops? Can they calculate at all?

At
Kyoto University, Tetsuro Matsuzawa's experiments are revealing that
chimps can in fact develop an astonishing facility for numbers. He first
trained a chimpanzee named Ai to touch the numeral that matched the number of
dots. Once Ai knew zero through nine, Matsuzawa displayed the numerals
helter-skelter on a screen. Ai quickly learned to touch them in ascending
order.

In
the final test, Matsuzawa piled on. As
soon as Ai touches the numeral one, white squares cover up the remaining
numerals. Can the chimp possibly remember all the locations and touch them in
order?

TETSURO
MATSUZAWA:
The performance was really
amazing. Much, much better than we had expected.

NARRATOR:
But for Ai, learning numbers was a struggle.

TETSURO
MATSUZAWA:
Almost the same amount of
training was necessary to teach three, teach four or teach five. Or, even worse,
it takes more time to teach five and then six.

NARRATOR:
Ai never got the "aha" feeling that
children have when they realize that you just add one to get to the next
number.

In
the United States, another ape shows a surprising gift for language.

SUE
SAVAGE-RUMBAUGH:
Going to go help get some
sticks? Good.

NARRATOR:
A bonobo named Kanzi, now at the Great Ape Trust
in Iowa, picked up English without being directly taught.

While
apes can master words and numbers, other research shows that something else is
limiting their cooperation: apes have emotional issues—rivalry,
violence—and most of all, they're impulsive.

In
a celebrated study that investigated impulse control, Sally Boysen of Ohio
State University asked chimps to choose between two dishes of M&Ms
®
.

SALLY
BOYSEN:
Now, you watch real carefully. We're
going to put one, two, three, four down here. Are you watching, Miss Priss? Sheeby?
And we're going to put two in here.

Give
those to Sarah. Okay.

Well,
I have to give these to Sarah, and Sheeba gets two. So Sarah gets four and
Sheeba only gets two. Aw, too bad.

NARRATOR:
The twist was that the chimp got the candy she
didn't point to. Could the chimp learn to resist her impulse to reach for
the bigger pile?

SALLY
BOYSEN:
You want Sarah
to have these? It's okay, it's okay. You get to have that one. Yeah,
Sarah gets five, and Sheba gets one. Oh, that is such a shame.

NARRATOR:
Amazingly, chimps never overcame their greedy
urges. They always reached for more and, so, ended up with less.

SALLY
BOYSEN:
And Sheba gets
two, so Sarah gets four. See?

NARRATOR:
Impulse studies have also been run on humans. In
a classic experiment from the 1970s, a researcher gave a four-year-old a simple
choice.

RESEARCHER
:
So, if you wait for me to get back, I'll
give you this bowl with all of these gummy bears, okay? But if you can't
wait, you can push that button, like this, and then I'll come back and
you can have this bowl with just this one gummy bear, okay? Okay, I'll be
right back.

NARRATOR:
According to an inconclusive but intriguing
study, the longer children resisted temptation, the higher their S.A.T. scores
were years later. In any case, the differences between people are small
compared to the gap separating humans and apes.

BRIAN
HARE:
Maybe one of the first things that happened during
our species evolution is we became much less emotionally reactive. And maybe
that's one of the big differences that may explain why we solve problems
so differently. We sort of got control of our emotions.

NARRATOR:
Can apes be given skills to help them master
their emotions? Sally Boysen trained a chimp to understand numerals. Then she
repeated her M&Ms experiment, but now offered different pairs of numerals
rather than treats.

SALLY
BOYSEN:
You want to give
two to Sarah? Okay. Two goes to Sarah, and you get six.

NARRATOR:
Remarkably, chimps were now able to learn what
they couldn't before: point to the smaller number to get the bigger
prize.

Symbols
can make you free. They can help distance an ape from its impulses. But outside
of the lab, apes don't seem to use symbols. Still, ape minds seem to
share many of the amazing features of the human mind. They have sophisticated
social emotions. They can cooperate. They have culture.

Their
mental rocket is on the launch pad. Why isn't it taking off?

The
human brain rocket certainly had lift-off. On an average day, human beings file
thousands of patents, post tens of thousands of internet videos, and think
millions of thoughts that have never been thought before.

Our
closest relatives are different. On a good day, an ape is lucky to use a tool
to crack a nut. What prevents ape culture from igniting like the human version?

Recent
studies that compare the human and ape minds are revealing something
surprising. Bonobos like Kanzi show their own kind of genius.

SALLY
BOYSEN:
Kanzi, could you
take off Sue's shoe? Could you take my shoe off, please? You might need
to untie it.

NARRATOR:
Even skeptics agree that Kanzi understands more
words than any other non-human animal. He also uses an array of visual symbols
to communicate. But on closer inspection, Kanzi, like all great apes, lacks the
full mental package.

Take
Kanzi's use of language.

JOSEP
CALL:
Most of the time, he will use these symbols to
request things, to say "Take me there," or "Give me that."
Now, Kanzi will not use those symbols to talk about the weather or to just make
small talk, which is a very human thing.

MICHAEL
TOMASELLO:
When human infants communicate
with others, they engage in a real conversation where each conversational turn
is responsive to the turn that came before. And they even ask for clarification
if they need. So you say "Huh?" or you say "Yeah," and
you let the other one know how the communication is going.

NARRATOR:
To engage in a real conversation, each speaker
needs a sense of what the other is thinking. Call this skill mind-reading.

Young
children haven't fully developed it.

RESEARCHER:
Hey, so Zoe, guess what we're
going to do today? We're going to play a game with my Princess Sally
here. See, this is Princess Sally. And she's got a ball that she really
likes. This is her ball. But she needs to go away for a little bit, so Princess
Sally is going to hide her ball right over here in the bag. See Princess Sally
hiding her ball right over there in the purple bag? Yeah?

So
here she goes. She's going to go away for just a little bit. Now while
Princess Sally is away, we're going to play a little trick on her, okay?
We're going to move her ball from the purple bag over here to the green
bag. See how we moved the ball over there? Okay, so guess what? Princess Sally
is coming back. Here she is. She came back. Can you tell me, where is Princess
Sally going to first look for her ball? Over here in the green bag? Can you
tell me, why is Princess Sally...

NARRATOR:
Classic studies showed that three-year-olds make
consistent mistakes about what others know.

REBECCA
SAXE:
The thing
that's amazing about three-year-olds is how convinced they are about
their wrong answer. They're so sure that she's going to look for
her ball where it really is because she wants it and that's where it is.

NARRATOR:
But by the age of four, most children are
accomplished mind-readers.

RESEARCHER:
Where is Sally first going to look for
her ball?

BOY:
She's going to look in the purple bag, so she
can find her ball.

SALLY
BOYSEN:
She's
going to look in the purple bag?

NARRATOR:
That's the right answer.

As
recently as 2001, studies seemed to show that apes don't know what others
are thinking. But then new experiments began to reveal unexpected skills.

In
one study, as a chimp approached a treat, Brian Hare moved it out of reach,
establishing himself as a competitor. Next Hare blocked his own view of one
treat but left another in his sight.

BRIAN
HARE:
It looks like they're generating a plan and
saying to themselves, "Okay, I want that food, and the one I'm most
likely to get is the one he's not looking at, or the one that, if I sneak
around, he won't see me, and therefore I can have my yummy banana treat."

NARRATOR:
This chimp seems to know what's on
Hare's mind, what he can see and what he can't. So chimps seem to
share a bit of our talent for mind-reading.

Do
we have any mental skills that are uniquely our own?

A
key clue comes from a new experiment. Back at the University of Texas, Victoria
Horner shows a chimp how to operate a puzzle box to get a piece of candy.

First,
she taps. Then she slides. Next she pokes.

The
chimp copies pretty well and gets the sweet.

DEREK:
This game we're going to play is about this
special box I brought, alright? There's a gummy bear. It's your
turn.

NARRATOR:
Children copy the actions, much as the chimps
did.

DEREK:
Look, you got him. Alright! There's the gummy
bear. Good job.

VICTORIA
HORNER
(Emory University/ University of St.
Andrews)
:
The second box that I
show the chimpanzees is this one, and it's identical to the opaque box
except that it's made out of material which is see-through.

NARRATOR:
Only now is it obvious that Horner's
tapping and poking don't achieve a thing: the box has a false ceiling.

The
chimps cut to the chase. They skip the needless steps. For the apes it's
all about the treat.

ANDREW
WHITEN:
What this study shows is that apes
don't just mindlessly ape. They also understand something more about
cause and effect.

VICTORIA
HORNER:
We found something quite
surprising. The children were pre-disposed to copy, even when it meant that
they were doing something that was really rather silly. So this seems a little
like the chimps are outsmarting the kids in this particular study.

DEREK:
There he is. You got him out.

NARRATOR:
Why do kids imitate slavishly?

VICTORIA
HORNER:
At the root of the children's
behavior is the fact that they viewed me as a grownup, possibly as a teacher.

NARRATOR:
That children expect to be taught is a vital
difference. While apes can copy, most researchers believe they don't
teach each other. Learning from someone else is the fastest way to get a new
idea: faster than learning by imitation, faster than inventing a new technology
in the first place.

In
children, a penchant for teaching appears—even before language kicks
in—in the form of a deceptively simply gesture: pointing. A toddler knows
that the cup being pointed to is the one that hides a treat.

REBECCA
SAXE:
Parents love
it when their kids start pointing because it's evidence that the kid's
trying to communicate with them. Parents definitely notice the difference
between babies who just point to ask for things and babies who point to show
them things.

NARRATOR:
Apes don't seem to get that kind of
pointing. It doesn't matter whether Brian Hare points or stares or
orients his body, this young bonobo can't fathom that he is trying to
communicate.

BRIAN
HARE:
They were clueless at using the information. Even
after lots and lots of trials, they didn't use the information I provided
them. And it was a big surprise to everybody.

NARRATOR:
But Hare suspected a certain domesticated animal
would succeed.

BRIAN
HARE:
I sort of was thinking to myself, "Well, wait
a second. I have a dog at home. And, you know, he plays fetch. And when he
loses his ball, he comes and looks at me. And if I point in a certain direction,
he runs off in that direction and tries to find the ball."

NARRATOR:
Sure enough, dogs get it.

Why
dogs and people but not apes? The answer may spring from the way emotions
collide with reason.

BRIAN
HARE:
It's possible that, like dogs, there may have
been selection against aggression in humans, and selection for tolerant
behavior, pro-social behavior, that actually then allowed us to use these
cooperative communicative cues in a very different way than other species, even
our closest relatives.

NARRATOR:
Pointing has a rational component too. It relies
on a particular mental skill, a little difference that makes a big difference.

BRIAN
HARE:
Whenever I point, I'm actually directing your
attention towards a third object. And you have to understand that my attention
is on that object, and that I'm asking you, now, to attend to the same
object. So there's sort of a triangle between us and the object.

NARRATOR:
This mental skill, call it "the
triangle," turbocharges teamwork.

MICHAEL
TOMASELLO:
What you'll see with the
human mother and baby is that the mother is constantly trying to show the baby
what to do, and the baby is trying to tune into what the mother wants. And so
you have a full triangle of mother and baby and the thing in the environment
that they are trying to work on.

REBECCA
SAXE:
It's a
special cognitive achievement. For some reason kids do this naturally, almost
immediately. And curiously, apes can't get into that.

MICHAEL
TOMASELLO:
At the moment we have no
evidence that apes have shared goals based on shared commitments. They do
things together, they coordinate their actions together, but they don't
have a shared commitment to a shared goal.

NARRATOR:
The triangle is the core skill that makes
teaching possible. Humans have it; apes seem to lack it. But apes are also
missing one more thing. It's a key emotional driver: the passion to cheer
each other on.

TETSURO
MATSUZAWA:
"Good," "good
job," "well done." This kind of facilitation, giving a hand,
encouragement, is the base of teaching.

REBECCA
SAXE:
It seems
like it's not just a cognitive capacity that's necessary for
teaching. There's this other thing, which is wanting to teach, that seems
to be really pervasive in humans and maybe mysteriously missing in apes.

NARRATOR:
The pieces are now coming together. Apes have
culture, a rare achievement in the animal world. They can learn from each other
by imitation. But this process is passive, often slow and can easily backslide.

BRIAN
HARE:
Probably there's a lot of slippage. There's
a lot of loss of cultural innovations between generations when you're
talking about a chimpanzee.

MICHAEL
TOMASELLO:
If an ape invents something new
and important and interesting, maybe some others will learn it, maybe they won't.

NARRATOR:
Unique among animals, humans have both the
passion and mental skill to teach each other. When you're a student
rather than a spectator, learning jumps to warp speed. That's because
teaching locks in progress.

MICHAEL
TOMASELLO:
Human culture traditions have a
cumulative quality that each generation builds on the things of the previous
generation. So if you looked at the history of any interesting technology, it
started out simple, and the children of that generation learned the simple
version. But then some genius made an improvement to it, and everyone follows
right away, and we get this ratcheting up in complexity.

NARRATOR:
An ape may stand on another's shoulders,
but only humans can stand on the intellectual shoulders of giants.

BRIAN
HARE:
It's such a great privilege to be able to work
with these animals and try to understand what's going on in their head
when they look at you so gingerly and softly. Is it they're thinking, "Oh,
he's such a nice guy, and boy, I wish I knew what was going on in his head?"
Or is she thinking, "Gosh, what's that spot? Is it dirt? Could I
eat that?"

NARRATOR:
In spite of their limitations, when we look into
the eyes of a fellow ape, we don't feel a gap but a deep connection. We
can't dismiss a chimp reaching out for help, or a group of unrelated
bonobos rallying to the defense of another, or a mother refusing to let go of
her dead baby. But as the most social of apes, we can't help reading
thoughts and feelings into the mind behind any familiar face.

And
perhaps that says more about us than them.

On
NOVA's
Ape Genius
Web site,
watch other tests of primate intelligence, hear about an amazing bonobo named
Kanzi, and more. Find it on PBS.org.

Major funding for NOVA is provided by David H.
Koch. And...

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